Threat (Long War)

The Aliens adjust their strategic operations based on how threatening they perceive XCOM to be. Threat determines which kinds of missions the aliens will run each month & the likelihood that a particular landed UFO will be a trap.

Threat Counter

A running tally of threat is incremented over the course of the month as XCOM successfully launches operations against alien UFOs.

• Shoot down or successfully assault a Scout, Fighter, Raider, Destroyer, or Abductor: +1
• Shoot down or successfully assault a Harvester, Terror Ship, Transport, Battleship, Assault Carrier, or Overseer: +2

This threat counter is used to determine the UFOs fielded in the following month as well as the likelihood that a particular landed UFO will be a Trap UFO in the current month.

At the beginning of each month, the threat counter is normally reset to 0. However, if it was 6-7 at the end of last month, it is set to 1, and if it was 8+ at the end of last month, it is set to 2 instead.

Trap UFOs

The chance of any particular landed UFO being a "Trap" is based on the current threat counter in the moment it lands. Thus, it is significantly lower in the beginning of the month when the counter is close to 0, but much more likely by the end of the month if XCOM has been diligent in shooting down UFOs.

Chance of Trap: Threat Counter / 30

For example, if the current counter is 5, the aliens have a 5/30 (16.67%) chance of a landed UFO being a trap.

Trap UFOs have significantly increased numbers of aliens; generally, the smaller and more unassuming the UFO type, the greater the relative increase. Traps can only occur when UFOs successfully land; UFOs that can't land aren't listed, and UFOs that get shot down will also never be traps.

Landed UFO Troop Counts
UFO Type	Regular	Trap
Scout	10-12	21-24
Raider	17-22	26-38
Abductor	22-29	32-49
Harvester
Transport	34-45	46
Terror Ship

UFO Missions

At the end of each month, the current Threat Counter, in conjunction with alien resource levels, determines the types of missions the aliens will field in the next month. In general, the total number of missions is more linked to resources, while threat level determines how aggressive those missions are, with the Aliens tending to target XCOMs satellites and engage in more Terror missions at high threat; see the missions table for details.

When determining the location of a Harvest mission, high threat may cause aliens to try and avoid XCOM's satellite coverage. This is represented by a chance that the aliens will reroll the target country if it has a satellite over it:

Threat	Chance
0-1	0%
2-3	10%
4-5	20%
6-7	30%
8+	40%

This reduces Alien Resources by 5. The reroll algorithm will always pick a random new location without a satellite. If no such location is available (i.e. XCOM has all 16 countries covered by a satellite), the reroll is canceled and no cost is accrued.